Don't know if this response is too late to be helpful, but the Touchstone will work with the i-wrapz. However, the sensor that detects when the phone is at your ear while talking was covered by the front panel, which made it impossible to use the touchscreen once a call was initiated, and made the i-wrapz unusable.

On a personal preference note, I also found it to add more bulk than I liked. I prefer either the seidio.com Innocase, a Gelaskin, or a Skinit. They are all good & add less bulk.